Dell OptiPlex 755 User Manual page 157

Power Cable Connectors
1 power cable
2 power input connector
Connecting and Disconnecting Drive Cables
When removing an cable with a pull-tab, grasp the colored pull-tab and pull until the connector detaches.
When connecting and disconnecting a SATA data cable, hold the cable by the black connector at each end.
Hard Drive
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before removing the computer cover.
NOTICE: To avoid damage to the drive, do not set it on a hard surface. Instead, set the drive on a surface, such as a foam pad, that will sufficiently
cushion it.
Removing a Hard Drive
1. If you are replacing a hard drive that contains data you want to keep, back up your files before you begin this procedure.
2. Check the documentation for the drive to verify that it is configured for your computer.
3. Follow the procedures in Before You
4. Remove the computer cover (see
5. Lay the computer on its side so that the system board is on the bottom of the inside of the computer.
6. Press in on the two blue securing tabs on each side of the drive and slide the drive up and out of the computer.
NOTICE: Do not pull the drive out of the computer by the drive cables. Doing so may cause damage to cables and the cable connectors.
7. Lift the drive out of the computer, careful not to pull the cables still attached to it.
Begin.
Removing the Computer Cover).